Effect of different storage temperatures on postharvest quality of cut flowers of tree peony 'Luo Yang Hong'

Tree peony (Paeonia suffruticosa) cut flowers are well known in China and have high potential market value. A large production base of tree peony grown for cut flowers has been built in China, but many postharvest handling problems exist, and optimum conditions for long term storage and transportation have yet to be determined. In order to identify the most suitable storage conditions and to better understand the mechanism of postharvest senescence of tree peony cut flowers, the effects of different storage temperatures on postharvest quality and physiological changes in cut flowers of tree peony 'Luo Yang Hong' were investigated. Branches with flowers at the bud stage were dry-stored at two temperatures of T1 (2 +/- 2 degrees C) and T2 (6 +/- 2 degrees C) for 49 d. During storage, flowers were removed at 7-day intervals to measure vase life, flower opening index, fresh weight loss, electrical conductivity (EC) and malondialdehyde (MDA) content. Flowers stored at T1 or T2 for 7 d maintained a post-storage vase life of more than 5 d, which was similar to that of non-stored (control) cut flowers, while those stored at T1 or T2 for periods of 14 or more days suffered significant loss in vase life. Flowers stored at T1 from 21-days had a longer vase life, and were able to open normally even after 49-days storage, than flowers stored at T2 that were unable to open normally after 35-days storage. The better postharvest quality achieved at lower storage temperature was associated with less fresh weight loss and lower EC and MDA content in cut flower petals.